1. Field of Invention
The present invention relates generally to the field of apparatus and methods for securing loading platforms, and more particularly to a bracing mechanism and method for securing loading platforms within shipping containers without the use of dunnage or complex tie down systems.
While the present invention is subject to a wide range of load securing applications, it is particularly well suited for securing loading platforms within International Standards Organization (ISO) shipping containers.
2. Technical Background
Shipping containers, and specifically ISO containers, have long been a standard vehicle for transporting equipment and other goods via air, land, sea, and rail. These containers are durable, rugged in construction, and are sized and shaped such that they are readily and economically securable to rail cars, trucks, ship holds, and cargo bay floors of large aircraft. Sufficiently bracing loads within these containers, however, has proved to be a challenging task.
In view of these load bracing issues, the United States Armed Services is moving toward the employment of a Container Roll-in/out Platform (CROP) as the load/unload platform for equipment and other goods carried in ISO containers. The M3 and M3A1 CROP each has a flat cargo body with a folding front end structure assembly designed for use with the Palletized Load System (PLS) truck and trailer. Each is designed to be loaded onto the PLS truck and trailer and into an ISO container using the Load Handling System (LHS). Each is also capable, however, of being transported by other modes of transportation through the supply distribution system in a stand-alone configuration.
A standard M3 CROP weighs approximately 3,800 pounds, while a standard M3 A1 CROP weighs approximately 4,000 pounds. The M3 CROP and the M3A1 CROP will accommodate payloads of approximately 32,450 pounds and 32,250 pounds, respectively, when loaded in an ISO container. Loaded CROPs are subjected to numerous forces during transportation, and despite their heavy weight, are often predisposed to shifting during transportation. The shifting, if unaddressed, results in loosening of the loads, which in turn results in damage to the loads, and can also result in damage to the CROP and ISO container as well. Accordingly, repeated contact between the CROP and ISO container can necessitate the replacement of these devices well before the normal end of their useful life.
In the past, shifting has been addressed in a number of ways. A common, albeit, time consuming method of securing loads and loading platforms such as CROPs within ISO shipping containers has been the use of dunnage both during and after loading. Typically, the loading platform is configured with the desired load and then loaded into the ISO container. Dunnage is thereafter positioned around the load and loading platform to secure the cargo against movement within the ISO container. Unfortunately, the random size, shape, and configuration of the various loads necessitates a variety of dunnage materials. Such dunnage occupies a great deal of storage space, has a limited useful life, and becomes costly to replace over time. Moreover, in forward battle areas, these materials are seldom available. In addition, common dunnage materials frequently are insufficiently rigid and/or resilient to adequately support the heavy loads within the ISO containers during extended distance deliveries. The uploading and off loading of the ISO shipping containers, as well as routine handling of the ISO containers causes the load to bear upon the dunnage, which over time, tends to deform, compact and/or dislodge the dunnage, which results in shifting loads. Continued motion causes larger shifts in the loads, which in turn results in damage to the load, loading platform, and/or the ISO container.
Attempts have recently been made to equip the loading platforms themselves with a locking mechanism designed to engage the inner walls of ISO containers to prevent movement of the platforms with respect to the containers. One such transport lock is welded to the front side or sides of the loading platform and is equipped with a plurality of shim plates. The shim plates are stacked horizontally with respect to the front side of the platform within a generally rectangular housing, and can be independently extended laterally of the housing and secured in an extended position. Once the loading platform has been completely loaded into the ISO container, the shim that is most closely aligned with the shoring slot on the interior of the ISO container is extended and locked into the slot in an attempt to prevent at least forward movement (i.e., movement in the direction of the ISO container doors) within the ISO container. Because there are no standards that require specific positioning of the ISO container shoring slots, the shims must be sufficiently slender to facilitate alignment with the slot. Thus, even when the shim is locked into engagement with the shoring slot, some amount of platform movement is permitted by the gap existing between the shim and the shoring slot. Additionally, if the shim is weak, this shifting may cause the shim to snap resulting in failure of the bracing. Moreover, on some occasions, multiple attempts at finally positioning the loading platform within the ISO container are needed to allow one of the plurality of shims to align with the shoring slot.
In view of the foregoing, there is a need for an apparatus and method for securing loading platforms, and thus the loads configured thereon, which obviates the shortcomings of other devices and methods currently know in the art. More specifically, there is a need for a bracing mechanism and method that mounts securely to existing loading platforms such as CROPs, and that securely engages the shoring slots of shipping containers such as ISO shipping containers. The bracing mechanism should have a finite length, but be infinitely adjustable over that finite length. Such a device should be simple to use, inexpensive to manufacture and maintain, readily attachable and detachable from existing equipment, and easy to transport and store when not in use. It is to the provision of such a device and method that the present invention is primarily directed.